Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases
Operating Lease ROU Assets	$ 855	$ 882	$ 0
Operating Lease Liabilities due Within One Year	199	204	0
Operating Lease Liabilities	668	$ 684	0
Total Operating Lease Liabilities	867
Finance Leases
Property, Plant and Equipment, at cost	259
Accumulated Depreciation	(50)
Property, Plant and Equipment, net	209
Long Term Debt and Finance Leases due Within One Year	6
Long Term Debt and Finance Leases	243
Total Finance Lease Liabilities	$ 249		$ 37
Weighted Average Remaining Lease Term
Operating Leases	7 years 2 months 12 days
Finance Leases	31 years 7 months 6 days
Weighted Average Discount Rate
Operating Leases	6.69%
Finance Leases	8.46%